Derivatives of 3-indazolone-oximes and 3-indazolone-imino sulphonic acids

ABSTRACT

INDAZOLE COMPOUNDS OF THE FORMULA   1,2-DIALKYL,3-(R-N=)-2,3-DIHYDRO-1H-INDAZOLE   IN WHICH THE ALKYL GROUPS IN THE 1- AND 2-POSITIONS ARE THE SAME OR DIFFERENT AND CONTAIN NO MORE THAN 4 CARBON ATOMS, WHEREIN R REPRESENTS AN OH OR SO3H RADICAL, AND THE NUCLEUS A IS UNSUBSTITUTED OR SUBSTITUTED BY HALOGEN ATOMS OR NITRO GROUPS, MAY BE USED EFFECTIVELY TO PRODUCE 1,2-DIALKYL-3-INDAZOLONE-IMONIUM SALTS WHICH ARE USEFUL AS INDAZOLIUM DYESTUFF INTERMEDIATES.

United States Patent US. Cl. 260-310 Claim ABSTRACT OF THE DISCLOSURE Indazole compounds of the formula A N-alkyl alkyl in which the alkyl groups in the 1- and 2-positions are the same or different and contain no more than 4 carbon atoms, wherein R represents an OH or SO H radical, and the nucleus A is unsubstituted or substituted by halogen atoms or nitro groups, may be used effectively to produce 1,2-dialkyl-3-indazolone-imonium salts which are useful as indazolium dyestuif intermediates.

The present application is a division of application Ser. No. 594,395 filed Nov. 15, 1966 and now abandoned.

The present invention concerns new heterocyclic compounds and dyestuffs resulting therefrom. In particular it relates to new indazole compounds which may be represented by the general formula:

in which the nucleus A may be substituted by halogen atoms or alkyl, alkoxy, nitro, sulphonamido, alkylsulphonyl, trifluoromethyl, 'cyano, amino, acylamino or bydroxy groups, the alkyl groups in positions 1 and 2 may be the same or different, and R represents an OH or SO H radical. The alkyl groups in positions 1 and 2 preferably contain no more than four carbon atoms.

The invention also relates to the imonium salts and the indazolium dyestuiie derived therefrom.

The intermediates according to the invention may be prepared by a process comprising two stages. In the first stage, hydroxylamine is reacted with 1,2-dialky1-indazolium salts of the general Formula II or IIbis) I e SOz a As A N-alky1 A N-alkyl N N a lkyl a lkyl n (IIbis) 3,557,139 Patented Jan. 19, 1971 ICC in which the possible substituents of the nucleus A and the alkyl groups in positions 1 and 2 are as defined above. In Formula II, Y is a chlorine or bromine atom and X is a monovalent anion or its equivalent. The hydroxylamine may be used in the form of one of its salts, such as for example the sulphate or hydrochloride, and the reaction may be carried out, for example, in an alcoholic medium in the presence of a tertiary amine such as for example triethylamine.

The reaction products of Formula Ia isolated in this first stage are 1,2-dialkyl-3-indazolone-oximes R=OH) in the case when an indazolium salt of Formula II is used. The reaction may be expressed as follows:

alkyl a) On the other hand, these products are of two types according to the substituents of A when hydroxylamine is reacted with 1,2-dialkyl-indazolium-3-sulphonates of Formula (IIbis).

Thus, in the case when A is substituted by a nitro group in positions 5 or 6, the reaction product formed is a 5- or 6-nitro-1,2-dialky1-3-indazolone-oxime (R=OH), according to the reaction On the other hand, when the nucleus A is not substituted or when it does not contain strongly electro-negative groups, the product isolated after the reaction contains sulphur. Having regard to the analytical results and the properties of the compound obtained, the latter may be considered as a 1,2-dialkyl-3-indazolone-imino-sulphonic acid (Le. a compound of Formula Ib when R=SO H). The reaction could be formulated as follows:

At all events, the intermediate compounds of Formulae Ia and Ib treated in the second stage of the process with anion-providing agents, such as for example phosphorus trichloride, phosphorus tn'bromide, phosphorus oxychloride or thionyl chloride or more simply even with dilute mineral acids, give according to the invention salts which may be represented by the Formula III, the formation of 3 which may be shown graphically by the two following reactions:

NOH l srrz x The compounds (III) may be equally considered either' as 1,2-dialky1 3-indazolone-imine or better 3 indazolone-imonium salts, or as 1,2-dialkyl-3 amino-indazolium salts, canonical forms of a mesomeric state:

I IHz X 1 1112 X NHZ N-alk N-alk l N-alk N/ \N/ KAN e alk alk alk The name 3-imoniurn-indazolone salts, which better takes into account both the imine character of the substituent in position 3 and the quaternary structure of the molecule, is preferably used here.

The salts of Formula III may also be obtained from compounds (II) and (IIbis) by the direct action of excess ammonia in aqueous solution.

The salts of Formula III are very soluble in hot water, from which they crystallise on cooling. The anionic nature of the radical X is demonstrated by the faculty it has of being exchanged with another anion such as for example, iodide, chromate, ferrocyanide or molybdate, for example by the addition of excess of the cor responding salts to aqueous solutions of the compounds of Formula III. When they are substituted by a nitro group, these compounds are easily reduced by any conventional reducing method and provide the corresponding amino derivatives. The latter, when subjected to hydrolysis in dilute sulphuric acid at temperatures between 160 C. and 200 C. give the hydroxy derivatives with good yields. This result shows the very great stability of these compounds in an acid medium.

On the other hand, the action of caustic alkalis in aqueous solution may cause opening of the ring and lead to ZN'-(Z-cyanophenyl)-N,N-dialkyl-hydrazines of Formula IV:

ON A l NNH-alkyl alkyl dimethyl-3-imine-indazolone formed is a colourless liquid of pKa 11.1, boiling at 172-173 C. at 15 mm.

The salts of Formula III are intermediate products which can be used for the preparation of dyestulfs, especially those which have an amino or hydroxy group in the 5 or 6 positions on the nucleus A.

The present invention also relates to the new azo dyestuffs derived from these intermediates and corresponding with the following general formulae:

alkyl (V) in which Y represents a hydrogen atom oran amino or hydroxy group, the alkyl groups and X have the same significance as above, and Ar represents an aromatic or heterocyclic residue not containing sulphonic or carboxylic groups and possibly substituted by halogen atoms or alkyl, alkoxy, trifluoromethyl, nitro, hydroxy, free or substituted amino, sulphonamido, aryloxysulphonyl or sul-- phohalide groups.

Among the dyestuffs of Formula V, those of the formula may be obtained by coupling the diazo compounds obtained from S-amino or 6-amino l,2-dialkyl 3-indazolone-imoniurn salts with coupling compounds of formula ArH. This coupling process is eifected by known methods in a neutral or slightly acid medium with amino coupling compounds and in a neutral or slightly alkaline medium with hydroxy or keto-enol couping compounds. The diazotisation of the 5- or 6-amino-1,2-dialkyl-3-indazolone-imonium salts is carried out very easily in dilute acid aqueous medium owing to their great solubility; The imonium group does not take part in this reaction.

The dyestuffs of formulae:

. I III alkyl alkyl III (VII) (VIII) A may be prepared by coupling a diazo compound of an amine of formula AINHZ, either in neutral or slightly acid aqueous medium with 5- or 6-amino-l,2-dialkyl 3-indazolone-imonium salts or in neutral or slightly alkaline aqueous medium with 5- or 6-hydroxy 1,2-dialkyl 3- indazolone-imonium salts.

The dyestuffs of the above Formulae VI, VII, and VIII show all the tinctorial properties of the cationic dyestuffs and in particular possess an excellent affinity for materials based on acrylonitrile polymers or copolymers, which they dye in very varied and generally very fast shades which range from greenish yellow to blue violet.

In the following examples, to which the invention is not limited, the parts are parts by weight unless the contrary is mentioned.

EXAMPLE 1 A mixture of 27.1 parts of -nitr0-1,2-dimethyl-3- indazolium-sulphonate, 14 parts of hydroxylamine hydrochloride and 42 parts by volume of triethylamine in 340 parts by volume of absolute ethanol is heated under reflux for half an hour. It is diluted with 1500 parts of water, and the precipitate formed is filtered off, washed and dried at 60 C. 16.5 parts of 5-nitro-1,2-dimethyl-3-indazoloneoxime are thus obtained in the form of deep red crystals, which are recrystallised from ethanol for analysis. M.P. 215 C. (Maquenne block).

Analysis.Calculated for C I-I N O (percent): C, 48.65; H, 4.50; N, 25.21. Found (percent): C, 48.6, 48.9; H, 4.58, 4.55; N, 24.7.

A mixture comprising 11.1 parts of this oxime, 50 parts of dimethyl formamide and 3 parts by volume of phosphorus trichloride is maintained at 30 C. for one and a half hours. The beige precipitate formed is filtered ofi and washed with absolute alcohol. The product is very soluble in water. It is recrystallised from methanol for analysis, and is identified as S-nitro-1,2-dimethyl-3-indazolone-imonium chloride, M.P. 290 C.

A.nalysis.-Calculated for C H ClN O (percent): C, 44.51; H, 4.53; N, 23.09; Cl, 14.63. Found (percent): C, 44.8; H, 4.69; N, 22.7; C1, 14.7.

On replacing the phosphorus trichloride in this process by thionyl chloride, under the same conditions 5.3 parts of the same compound, M.P. 290 C., are obtained.

On boiling a mixture of 11 parts of the same oxime, 50 parts of water and parts by volume of 10 N hydrochloric acid, complete solution is obtained in some moments. On cooling, :1 salt identical with the previous ones crystallises, 10.8 parts being thus obtained.

On treating an aqueous solution of this salt with a solution of sodium dichromate, the instantaneous precipitation of bright black crystals of 5-nitro-1,2-dimethyl-3- indazolone-imonium chromate is observed, which may be recrystallised from dilute ethanol.

Analysis.Calculated for C H N O (CrO /2 (percent): N, 21.13. Found (percent): N, 20.95, 21.03.

The action of the caustic alkalis on the 5-nitro-1,2- dimethyl-3-indazolone-imonium chloride is illustrated as follows:

22 parts of S-nitro-1,2-dimethyl-3-indazolone-imonium chloride are dissolved in 300 parts of water at 50-60 C., and parts by volume of a 10 N solution of caustic soda are added. A red crystalline precipitate is instantaneously formed which after cooling is filtered off, washed and dried at 65 C. The yield is practically quantitative. The product is sparingly soluble in water, and very soluble in organic solvents, and reduces Fehlings solution. On recrystallisation from methanol it melts at 117 C.

Analysis-Calculated for C H N O (percent): C, 52.43; H, 4.85; N, 27.19; 0, 15.52. Found (percent): C, 52.4, 52.1; H, 5.6, 5.1; N, 26.7; 0, 15.9.

The same product is obtained by condensing 2-chloro- 5-nitro-benzonitrile with 1,2-dimethyl hydrazine djhydrochloride in a boiling alcoholic medium in the presence of triethylamine. The red compound thus obtained is in an unstable form (M.P. 78 C.) which recrystallises and this time melts sharply at 117 C. The mixture of the two products melts at 117 C. The same compound, N- (4-nitro-2-cyanophenyl)-N,N'-dimethyl hydrazine, is then found to be present. This compound (not yet described), when treated with dilute hydrochloric acid even in the cold cyclises with re-formation of 5-nitro-l,2- dimethyl-3-indazolone-imonium chloride, M.P. 290 C. (mixed M.P. shows no lowering of M.P.).

Analysis-Calculated for C H O N Cl (percent): C, 44.51; H, 4.53; N, 23.09; Cl, 14.63. Found (percent): C, 43.9; H, 4.9; N, 22.8; C1, 14.2.

300 parts by volume of 28 B. ammonia are introduced at 5 C. with stirring into a suspension of 300 parts of S-nitro-1,2-dimethyl-3-indazolium-sulphonate. Stirring is continued for 16 hours, then a red precipitate is filtered off which, after washing and drying, weighs 75 parts and is impure 5-nitro-1,2-dimethyl-3-indazolone (M.P. 177 C. after recrystallisation from water). The filtrate from the operation is made acid by the addition of hydrochloric acid. On cooling a crystalline precipitate of S-nitro-1,Z-dimethyl-3-indazolone-imonium chloride is formed. Weight after filtering and drying 124 parts.

EXAMPLE 2 48 parts of S-nitro-l,2-dimethyl-3-indazolone-imonium chloride are introduced in small quantities over a period of 45 minutes into a mixture comprising 200 parts of water, 30 parts of iron powder and 2 parts of 10 N hydrochloric acid, previously boiled for a few minutes.

The mixture is boiled for two hours, allowed to cool and sodium carbonate is added until the pH is 8 or 9. It is filtered, the iron hydroxide sludge is washed with about 200 parts of water, and the filtrate is cooled and 40 parts of sodium chloride are added to it. This addition causes the crystallisation of slightly yellowish white crystals of S-amino-1,2-dimethyl-3-indazolone-imonium chloride. These are filtered ofif, washed with a concentrated brine solution, drained and dried at for example between 60 C. and C. 45 parts are thus obtained which are recrystallised from methanol for analysis.

Analysis.-Calculated for C H ClN H O (percent): C, 46.82; H, 6.51; N, 24.28; Cl, 15.35. Found (percent): C, 47.5; H, 7.1; N, 24.2, 24.7; C1, 15.7, 15.6.

EXAMPLE 3 On replacing the 5-nitro-1,2-dimethyl-indazolium-3- sulphonate in Example 1 by 6-nitro-1,2-dimethylindazolium-3-sulphonate and operating under identical conditions, there are obtained successively, 6-nitro-1,2- dimethyl-3-indazolone-oxime, red crystals of M.P. 166 C. after recrystallisation from methanol.

Analysis-Calculated for C H N O (percent): C, 48.65; H, 4.50; N, 25.21. Found (percent): C, 49.0, 49.0; H, 4.89, 4.72; N, 25.1.

And 6-nitro-1,2-dimcthyl-3-indazolone-imonium chloride, beigecrystals of M.P. 275 C. after recrystallisation from methanol.

Analysis.Ca1culated for C H ClN O (percent): C, 44.5; H, 4.53; N, 23.09; Cl, 14.63. Found (percent): C, 44.8; H, 5.36; N, 23.3, 23.0; C1, 14.2.

On replacing in the two last paragraphs of Example 1 the S-nitro 1,2 dimethyl-3-indazolone-imonium chloride by its 6-nitro isomer one obtains under the same conditions N'-(5-nitro-2-cyano-phenyl) N,N' dimethylhydrazine in the form of red needles of melting point 162 Analysis.Calculated for C H N O (percent): C, 52.43; H, 4.85; N, 27.19. Found (percent): C, 52.4, 52.6; H, 5.2, 5.4; N, 26.9.

The imonium salt being formed again by hydrochloric acid treatment. On mixing with the initial salt, the melting point is not lowered.

Analysis.Calculated for C H ClN O (percent): C, 44.51; H, 4.53; Cl, 14.63. Found (percent): C, 44.9, 44.8; H, 4.80, 4.63; Cl, 14.1.

EXAMPLE 4 On replacing the 5-nitro-1,2-dimethyl-3-indazoloneimonium chloride in Example 2 by its 6-nitro isomer prepared according to Example 3 there is formed under the same conditions 6-amino 1,2 dimethyl-3-indazoloneimonium chloride in the form of pale beige crystals which are very soluble in water.

Analysis.Calculated for C H ClN (percent): C, 50.80; H, 6.12; N, 26.36; Cl, 16.70. Found (percent): C, 50.4; H, 6.3; N, 25.8; CI, 16.7.

When a solution of potassium iodide is added to a solution of the above salt, crystals of the corresponding less soluble iodide are formed.

Analysis.Calculated for C H IN (percent): C, 35.53; H, 4.28; N, 18.42; I, 41.76. Found (percent): C, 36.0;H, 4.33; N, 18.2; I, 42.6.

EXAMPLE 5 A solution of parts of 6-amino-1,2-dimethyl-3-indazolium-imonium chloride in 90 parts of water and 8.8 parts by volume of 66 B. sulphuric acid are heated at 180 C. for '6 hours in an autoclave. The mixture is allowed to cool to 100 C. and the autoclave is opened, a little active carbon is added and the product is filtered and the filtrate cooled. A first crystalline fraction is thus obtained of 6-hydroxy-1,Z-dimethyl-3-indazolone-imonium chloride, which is filtered oil, washed with a saturated solution of sodium chloride, drained and dried in an oven. Dry weight: 13.5 parts. A second fraction of the same salt, viz. 2.3 parts, is obtained by the addition of 20 parts of sodium chloride to the mother liquors. The product is recrystallised from methanol or water for analysis.

Analysis.-Calculated for C H ON Cl /2H O (percent): C, 48.52; H, 5.84; N, 18.87; Cl, 15.96. Found (percent): C, 48.2, 48.7; H, 5.64, 5.83; N, 18.9,19.1;Cl, 16.0, 15.9.

EXAMPLE 6 A solution of 20 parts of 5-amino-1,2-din1ethyl-3-indazolone-imonium chloride in 90 parts of water and 8.8 parts by volume of 66 B. sulphuric acid is heated to 200 C. for 6 hours in an autoclave. The product is allowed to cool to 100 C., a little active carbon is added, and it is filtered and 20 parts of sodium chloride are added to the filtrate, and it is filtered after cooling. The crystalline precipitate is taken up in boiling absolute ethanol in order to separate the mineral salts and the filtered solution is evaporated to dryness. 14.4 parts of 5-hydroxy-1,2-dimethyl-3- indaZolone-imonium chloride in the form of white crystals which are very soluble in water are thus obtained. The aqueous solution has a blue fluorescence. The product is recrystallised from ethanol for analysis.

Analysis.Calculated for C H CIN O (percent): C, 50.60; H, 5.62; N, 19.67; Cl, 16.61. Found (percent): C, 51.1, 51.0; H, 6.2, 5.97; N, 19.8, 20.1; C1, 16.2.

EXAMPLE 7 A mixture of 45.2 parts of 1,2-dimethyl-indazolium 3- sulphonate, 28 parts of hydroxylamine hydrochloride and 84 parts by volume of triethylamine in 700 parts by volume of absolute ethanol is refluxed for half an hour. It is then poured into 3000 parts of water and 750 parts of salt are added. The mixture is cooled and the white crystalline precipitate is filtered off, dried and recrystallised from methanol. Dry weight obtained: 30 parts. This product probably consists of 1,2-dimethyl-imino-indazolone-3- sodium sulphonate crystallised with half a molecule of Wa- 16)..

Analysis.Calculated for C H N O SNa /2H O (percent) :C, 39.70; H, 4.04; N, 15.43; Na, 8.47. Found (percent): C,'39.9; H, 4.31, 4.27; N, 15.57, 15.39; Na, 7.8.

10 parts of this compound are heated under reflux for half an hour in parts of water and 7.5 parts by volume of 10 N hydrochloric acid. On cooling, white crystals of 1,2-dimethyl-3-indazolone-imonium chloride are precipitated, and are filtered off and dried in an oven. Dry weight obtained: 7 parts, which may be recrystallised from absolute ethanol for analysis.

Analysis.Calculated for C H ClN (percent): C, 54.68; H, 6.08; N, 21.25; Cl, 17.98. Found (percent): C, 54.9, 54.7; H, 6.16, 6.02; N, 21.6, 21.7; C1, 17.7.

When an aqueous solution of the last compound is treated with caustic soda, a colourless oil separates which consists of 1,2-dimethyl-3-indazo1one-imine. After drying and distilling, the product boils at 172l73 C. under 15 Analysis.-Calculated for C H N (percent): C, 67.08; H, 6.83; N, 26.07. Found (percent): C,'67. 5, 67.8; H, 7.02, 7.38;N, 25.5.

When taken up in concentrated hydrochloric acid, this oil forms a white precipitate which is recrystallised from water, then from ethanol. The 1,2-dimethyl-'3-'indaz olone-imonium chloride described above is recovered.

Analysis. Calculated for C H 'ClNg' (percent): C, 54.68; H, 6.08; N, 21.25; C1, 17.98. Found (percent): C, 54,9, 54.8; H, 6.02, 6.37; N, 21.4, 21.3; C1, 17.5.

EXAMPLE 8 under the conditions described in Example 7, leads to 1,2-

dimethyl-5-chloro-3-indazolone-imonium chloride, which is recrystallised from ethanol for analysis.

Analysis.-Calculated for C H Cl N (percent): C, 46.55; H, 4.74; N, 18.10; Cl, 30.6. Found (percent): C, 46.3, 47.2; H, 5.09, 5.17; N, 17.9, 18.1; C1, 30.2.

EXAMPLE 9 On operating as in Example 1 with 119 parts of 5 ,7-dichloro-1,2-dimethyl-3-indazolium-sulphonate in 1400 parts by volume of absolute ethanol, 165 parts by volume of trimethylamine and parts of hydroxylarnine hydrochloride one obtains 39 parts of 5,7-dichloro-1,2-din1ethylindazolone-oxime which are recrystallised from ethanol for analysis to give white crystals, M.P. 105 C.

Analysis.-Calculated for C H CI N O (percent): C, 43.86; H, 3.66; N, 17.07; Cl, 28.87. Found (percent): C, 43.9, 43.8; H, 3.81, 3.89; N, 16.9, 16.7; C1, 28.4, 280.

When 32 parts of this oxime are boiled for 5 minutes in a mixture of 20 parts by volume of concentrated hydrochloric acid and 150 parts of water, it gives after cooling a white crystalline precipitate of 5,7-dichloro-1,2-dimethyl- 3-indazolone-imonium chloride which is recrystallised from methanol for analysis.

Analysis.Calculated for C H Cl N (percent): C, 40.50; H, 3.75; N, 15.74; Cl, 39.98. Found (percent): C, 40.5, 40.8; H, 3.59, 3.69; N, 16.0, 15.7; C1, 39.5, 39.3.

EXAMPLE 10 8.3 parts of diethylamine are introduced into a mixture of 5.2 parts of 1,2-dimethyl-3-chloro-6-nitro-indazolium chloride, 2.7 parts of hydroxylamine hydrochloride and parts by volume of absolute ethanol. The mixture is boiled for half an hour, poured into parts of water, cooled in ice and the red precipitateformed is filtered oflf. It is 6- 11itr0-1,2-dimethyl-3-indazolone-oxime of MP. 166 C. already obtained in Example 3.v

EXAMPLE 1 1 6.4 parts of 1,2-dimethyl-6-amino-3 indazolone-imonium chloride and 2.1 parts of sodium nitrite are dissolved in 100 parts of water. This solution is introduced while stirring into a mixture maintained at between 0 C. and 5 C. of 100 parts of Water and 10 parts by volume 'of 10 N hydrochloric acid. Stirring is continued for 20 minutes, the slight excess of nitrous acid 'is destroyed by theaddition of sulphamic acid, and the diazo solution is poured into a solution of 5.6 parts of N-diethylaniline in parts of water and 3 parts by volume of 10 N hydrochloric acid.

Then in order to finish the coupling pr0cess,' a solution of sodium acetate is introduced until the excess hydrochloric acid has been neutralised. The diazo compound disappears rapidly and the dyestutl is precipitated. It is filtered off, washed with 10% brine, drained and dried at 100 C. Weight obtained: 8.3 parts of a dyestufr which is very soluble in water. 5 A solution of 0.5 parts of this dyestufi in 200 parts of water is prepared. 2 parts of acetic acid containing 60 g. per litre and 0.5 part of a product of condensation of caster oil with ethylene oxide are added. 100 parts of fibres based on acrylonitrile polymer are introduced at 50 C., the bath is brought progressively to the boil and maintained at this temperature for an hour and a half. A bright red shade endowed with excellent general fastness is obtained.

EXAMPLE 12 15 The coupling compound in Example 11 is replaced by a solution of 3.12 parts of 3-methyl-5-pyrazolone in 120 parts of N/2 caustic soda. Running the diazo compound into this solution causes the instantaneous forma- 20 tion of a yellow dyestutf. 60 parts of sodium chloride are added and the dyestufi is filtered 01f, drained and dried in an oven. Dry weight obtained: 7.8 parts of a dyestuif dyeing acrylic fibres a bright greenish yellow shade of excellent general fastness.

In the following table some dyestuifs prepared in a similar way with the same diazo compound are grouped together.

Shade on acrylic 3O Coupling compound fibres On replacing 1,2-dimethyl-6-amino-3-indazolone-imonium chloride in Example 12 by its S-amino isomer one 40 obtains under the same conditions a dyestufi which dyes acrylic fibres in fast yellow shades.

10 EXAMPLE 19 A well homogenised paste of 13.8 parts of finely ground p-nitraniline, 50 parts of water and 7 parts of sodium nitrite is introduced in fractions into a well stirred mixture of 250 parts of water and 40 parts of 10 N hydro chloric acid maintained at between 5 C. and 10 C. After stirring for half an hour, the slight excess of nitrous acid is destroyed by the addition of sulphamic acid and the diazo compound is filtered and introduced into a solution of 25 parts of 1,2-dimethyl--amino-3-indazolonetion of 25 parts of 1,2 dimethyl-5-amino-3-indazolonetemperature. The coupling is finished by neutralising the excess of hydrochloric acid by adding a solution of sodium acetate. The precipitated dyestuff is filtered off, washed with brine, drained and dried in an oven. Dry weight obtained: 35 parts. It dyes acrylic fibres in violet shades having excellent general fastness.

EXAMPLE 20 On replacing the coupling compound in Example 19 by its 6-amino isomer one obtains under the same conditions a dyestuff which dyes acrylic fibres in fast orange shades.

EXAMPLE 21 On running a diazo compound prepared as in Example 19 into a solution of 24 parts of 1,2-dimethyl-5-hydroxy- 3-indazolone-imonium chloride in 250 parts of water, and neutralising the excess of free acid by slowly running a solution of trisodium phosphate into the mixture, a precipitate dyestuff is obtained which is filtered 01f, drained and dried in an oven. Dry weight obtained: 38 parts. It dyes acrylic fibres in violet shades having excellent general fastness, especially to light.

EXAMPLE 22 On replacing the coupling compound in Example 21 by its 6-hydroxy isomer one obtains under the same conditions a dyestutf which dyes acrylic fibres a bright orange.

In the following table a number of examples analogous to the four preceding examples are grouped together.

Shades on acrylic fibresCoupling compound:

Y CH3 Diazo compound Ex. Y=NH:45 Ex. Y=NH2-6 Ex. Y=OH5 Ex. Y=OH6 m-Nitraniline 23 Red 24 Golden yellow 25 Scarlet 26 Golden yellow o-Nitraniline. 27 Bordeaux 0 range yellow 29 Ruby 30 Orange. p-Ohloranlline 31 Brownish red Yello 33 Bright red 34 Bright orange. m-Chloraniline 35 Bluish red Orange. o-Chloraniline 39 d Do. 2,5-dichloroaniline 43 D o. 3,4-dichloroaniline..- 47 Golden yellow. p-Anisl line 51 Orange. m-Anisidine 55 do Do. o-Anisidine 59 Brownish red Orange brown. p-Toluidine 63 Orange. m-Toluidine- Do. o-Toluidine do Orange yellow. p-Cresidine Purplish red Brown yellow. Reddish orange 2-methy l-4-chloro-anlline 78 ed 79 Golden yellow Golden yellow. 2-methoxy-5-chloro-aniline 82 Red violet 83 o-- Bright orange 2-methoxy-4-nitro-aniline 86 Lavender blue 87 Red orange 89 Bright red orange 2-methoxy-5-nitroanillne 90 Bordeaux 91 Golden yellow Orange yellow. 4-methoxy-2-nitroaniline- 94 Brownish red 95 Brown yellow- Bright orange red. 2-methy l-4-nitroaniline 98 Lilac 99 Orange Bright; orange. 4-methy l-2-nitroaniline. 102 Purplish red 103 Orange yellow. Orange. 2,4edimethyl-3-nitroaniline 106 Red 107 Golden yellow- Orange yellow. 2,4-dimethoxyaniline Reddish orange. -sulphonamidoaniline 112 Brownish red 113 Golden yellow Orange yellow 3-sulphonamldoaniline 116 Pale scarlet 117 Yellow Golden yellow. 4 phenoxysu1phonylan 120 Bordeaux 121 Golden yellow Orange yellow. 4-sulphofluoroaniline. 124 Purpllsh red 125 o Do. B-tritluoromethylanilin 128 carlet 129 Yellow Golden yellow. 2-tritluoro1nethyl-4-ehlor 132 Bluish red 133 do Do. p-Aminoazobenzene 136 Currant 137 Brownish orang Orange.

A homogeneous paste obtained b3} mixing 8 parts of the dyestufi described in Example 11, parts of acetic acid and 30 parts of thiodiglycol' is poured into 372 parts of Water at C. 50 parts of thiourea are added to t e a l t 9n b li .5.P@ .t O a t ken based on swollen gum "tragacanth and fin aIly 'IO parts of a 50% solution of sodium chlorate.

The paste thus obtained is printed on a polyacrylonitrile fabric, the fabric issteamed for 15 to 20 minutes at a temperature between C. and C., rinsed in running water, then soaped in a bath containing 2 to 3 g. per litre of Marseilles soap. After drying a bright red print of excellent general fastness is obtained.

We claim:

1. An indazole compound of the formula:

" References Cited 5 "UN T DS E RATE TS.

2,964,402 12/1960 Jennerret a1. 26(l-310B 'f y "FQ I N" PAT N S. 5 1,006,315 9/1965 Great Britain 260-310B H m OTHER REFERENCES Berget a1.: Jour. Chem. Soc. (London), 1961, pp. 52754 and 5281.

Parnell: 'Jour. Chem. Soc. (London), 1959, pp.

NATALIE 'rRousoF, Primary Examiner US. Cl;'X.R. 

